Shimadzu Corporation

Yoshihiko Kumazawa

Tsunekazu Matsuyama

Kazumi Tanaka

A first image collection memory collects two-dimensional image data within a predetermined energy window to constitute a fine matrix. A second image collection memory collects three-dimensional image data, including energy spectral information, to constitute a coarse matrix. Each pixel of the data collected in the second image collection memory is subjected to a scatter correction with energy weighted acquisition using a weight function. Correction coefficients are derived from a ratio between data before the correction and data after the correction, and by interpolation processing for each pixel in the fine matrix, and are applied to the image data collected in the first image collection memory. The data collected in the second image collection memory is subjected to two-dimensional low-pass filter processing. The scatter correction with the energy weighted acquisition is effected for each data collected in the second image collection memory such that the function is applied to the data before the filter processing, or after the filter processing.

Nuclear medicine imaging apparatus

Apparatus for stabilizing the amplification degree of photomultipliers

Semiconductor radiation detector comprising a radiation detecting element made of a compound semiconductor and operable at room temperature in response to a radiation event to produce a corresponding output signal; a preamplifier for preamplifying the output from the detecting element to produce a corresponding signal; and pulse shaping amplifier including a quasi-gaussian filter comprising a combination of a first differentiator and an integrator to shape and amplify the signal from the preamplifier; means for obtaining information about charge collection time at each radiation event by comparing the pulse height of a signal caused by the output from the differentiator and the pulse height of the output from the shaping amplifier; and means for correcting the pulse height of the output signal form the shaping amplifier in accordance with the information about charge collection time at each radiation event, thereby to improve the deterioration of the energy resolution caused by incomplete charge collection. There is also provided a semiconductor position-sensitive radiation detector which employs a plurality of the above-mentioned compound semiconductor radiation detecting elements so arranged in row and column as to form a matrix and which can be used effectively, for example, in nuclear medicine.

Semiconductor radiation detector

A radiation imaging apparatus provided with a pulse height analyzer for checking whether the pulse height of the energy signal produced in response to each scintillation event falls within an energy window set for the particular (x,y) coordinate position of the scintillation. The pulse height analyzer has a memory for storing a plurality of energy windows each for a particular one of the coordinate positions in the scintillator and each having a particular central level and a particular width such that the nonuniformity of the sensitivity of the detector due to the position-dependency of the energy signal and/or other causes can be corrected. A preliminary pulse height analyzer may be provided to increase the counting rate of energy signals useful for image production.

Growing community of inventors

Kyoto, Japan

Yoshihiko Kumazawa